POTSDAM, N.Y. (AP) — A retired music school professor says he was told to stop playing holiday songs on his trumpet while collecting for the Salvation Army outside a Walmart in northern New York.

Robert Gibbs, an 81-year-old retired professor from the State University of New York’s Crane School of Music, said managers at the Walmart in Potsdam told him Thursday that he could not play his horn at his kettle.

Gibbs said he’s made good money for the Salvation Army playing Christmas carols and holiday standards like “White Christmas” outside the store for years.

“It was kind of nice because little kids would come up, maybe the first time they’ve heard live music and those old carols,” Gibbs said Friday. “And then I’d ring the bell and the money would pour in because they felt sorry for this old guy.”

“I don’t want to toot my own horn, but it is nice,” he said.

Walmart Inc. spokeswoman Kayla Whaling said rules developed with the Salvation Army for the benefit of volunteers, shoppers and employees exclude musical instruments for kettle volunteers. The company wants to provide a distraction-free environment for customers, she said.

“We understand that some bell ringers have developed a unique way to help bring in some holiday cheer,” Whaling said. “However, the plan we developed with the Salvation Army excludes music and musical instruments.”

Whaling added that more than 4,000 Walmart and Sam’s Club stores take part in the Salvation Army program and that the stores helped raise more than $46 million last year.

“We’re sorry that the singing and playing of musical instruments is now being prohibited, but we’re following the guidelines that Walmart has asked us to follow,” said Christine Gray, a spokeswoman for the Salvation Army in New York. She said she was sure Gibbs would be asked to ring his bell at another location.

Gibbs, who has been playing the trumpet for 72 years, was thinking about performing outside a grocery store.